Tests 1-4: Baseline, new intake manifold, roller-tip rockers, retard cam 2-degrees (October 2002).
Test 1: This represents what a typical 355-cid small-block would make if it had just been blueprinted but still had most of its stock components.Max 395 tq, 308 hpAvg 376 tq, 266 hp
From this point on, except for the changes listed, nothing else was touched.
Test 2: We installed a Weiand PN 8004 dual-plane intake manifold and leaned out the Q-jet.Max 394 tq, 325 hpAvg 380 tq, 270 hp
Test 3: We replaced the stock stamped-steel rocker arms with COMP Cams 1.5:1 roller- tip Magnum rockers.Avg 390 tq, 278 hp
Test 4: We retarded the cam 2 degrees.Max 405 tq, 349 hpAvg 390 tq, 278 hp
Tests 5-8: Bigger 1 3/4-inch headers, full-roller rockers, bigger XE256H cam, stud girdle added (November 2002).
Test 5: Installed larger 1-3/4 Hooker headers. Compare Tests 4 and 5 and you'll see that average torque was down by 2 lb-ft, but peak toque and horsepower were up slightly, and average horsepower increased by 9. That's a fair trade to us.Max 407 tq, 351 hpAvg 388 tq, 287 hp
Test 6: Swapped in COMP Cams full-roller 1.5:1 aluminum rocker arms. Peak and average power didn't change at all (compare Tests 5 & 6), but we did get 5 more lb-ft of torque at 3,200 rpm.Max 407 tq, 351 hpAvg 389 tq, 288 hp